The primary objective of the study is to measure the effect of use of combined oral contraceptive (COC) or depo-medroxyprogesterone acetate (DMPA) on the acquisition of my infection, by comparing the rate of infection among women using COCs or DMP A with the infection rate among otherwise similar women who do not use hormonal contraception. The secondary objectives of the study are: 1) to determine if the rate of my infection in hormone contraception (HC) users compared with non-users is modified by the presence or duration of other sexually transmitted diseases, and to measure whether the type of hormonal contraception (COC versus DMP A) has a differential impact on the rate of STD acquisition among women;and, 2) to examine contraceptive hormones and their effect on other factors which have been shown to influence my transmission (e.g., bacterial vaginosis, genital shedding). The tertiary objective is to acquire, preserve, store and ship serum, plasma and peripheral blood mononuclear cells for subsequent viral isolation and genetic/antigenic characterization in support of HIVNETs HIV-l vaccine development initiative.